Spider gears notchey/hard to turn

[84yoda]

Is it just me or does anyone notice when you tighten the ring gear to the diff cup, the spider gears get notchey and hard to turn the outputs (with or without diff fluid)? Anyone figure how to keep this from happening? Or is everyone just running it? Wonder if 2 gaskets in front of the ring gear would help it. My rear does it but I just ran it but now I'm rebuilding my front and its doing the same thing.

[Trifish]

You are probably tightening the ring gear to much. I did it the 1st time I did some maintenance on my diffs. You want it snug but not too tight b/c its pinching your gears together inside the cup.

[SeanKewley]

Two gaskets, or just don't tighten down the 4 screws as much. I just finger tighten mine. Crunchy feeling is due to over tightening screws

[tonyfalkon]

You've over tighten it check the overall length between the 2 bearings should be at least 40 mm, you go lower than that you've already compressed the gasket too much and your planetary gears will start crunching or will lock itself. Putting another gasket might do the trick but making sure 40 mm OAL between the bearings should prevent that. On the bright side if you've always wanted a locked differential that's one way to do it. LOL

[SeanKewley]

LOL. Same three responses all within minutes of each other. We must have all hit reply around the same time.

[84yoda]

Trust me, I tried it all and still wasn't smooth like I'd expect it to be. I guess I'll try 2 gaskets and see how that is. Just finger tight worrys me since that diff is spinning a lot of rpm. I might pick up a new plastic diff cup so it'll have new threads and I'll feel better leaving it finger tight.

[pro mod steve]

Just a brain fart but are the outer gears fully seated over the drive pin?

[84yoda]

Yes. If I put everything together, attach ring gear and get bolts started, everything is fine. As soon as I tighten them AT ALL, it gets notchey. If I back 4 screws out so the screw heads aren't touching, its fine again.

[pro mod steve]

IDK just a thought.

[cmbscx10]

While i don't disagree about over-tightening the ring gear IMO that is not 100% the issue. If the thought is that over-tightening a .10mm gasket leads to notchy planetary or spiders gears then there would be no issue with the YXL due to Axial's over engineering every piece with apectacular tolerances on any vehicle they have ever produced.

When i assembled my YXL diff i was thankful i had a lot of shimming experience from my Losi 8T, SCTE 2.0 and XXL. What i found was that you may need to shim the Planetary, Spider gear or both. While using a outside measurement of out drives is a good idea i found that after a run or two either the oring would swell, compress more or ?? along with gear wear would change the mesh all together so shimming in .05 increments helped.

[redsawacs]

Assemble it and drive it in circles for an hour. If it breaks, call Axial CS and get new gears and cups

[84yoda]

I guess if I shim opposite side without the ring gear, behind the bearing so that it would push the output cup a hair over, then tighten the ring gear screws wouldn't cause it to get notchey. Ya?? Lol.

[84yoda]

Originally Posted by redsawacs

Assemble it and drive it in circles for an hour. If it breaks, call Axial CS and get new gears and cups

[BarHarborBasher]

I've had serious wear on the output washers !! Internal compression overload !! Also remember to vent the diff cup through the pin port when tightening down the ring gear to prevent hydraulic pressure (deforms the cup & snaps screws)

[BarHarborBasher]

I'm gonna take a spare cup and sand it down to create a perfect shim.. I'll let ya know my progress or someone can tackle it first... Getting backed up here lol

[tonyfalkon]

The 4 planetary gears come with shims on the back removing them will give you extra 0.3 mm, 40 mm OAL length between the 2 outer bearing and put a new gasket or add another to the old they are 0.5 mm unused once you tighten them, gaskets won't return to their original width LOL.

[BarHarborBasher]

I've removed the shims and added two NEW gasket a wile ago... Not a game changer... Something simple like that should be tried instead of suggested then reported..

[tonyfalkon]

Originally Posted by BarHarborBasher

I've removed the shims and added two NEW gasket a wile ago... Not a game changer... Something simple like that should be tried instead of suggested then reported..

I did ... probably one of the reasons why I have a good bevel and pinion mesh, also why I have not needed to shim my diff pinions or had the need to switch to spiral cut gears yet. As I understand it the OP is asking for tips and/or tricks that other members have tried and worked for them, and that's all I'm doing, I wouldn't have suggested it to him if I haven't tried it on my RTR as well.

[BarHarborBasher]

Completely prepared my self for a answer like that...please post a video of you mod so we can learn as a community

Try a set of HD gears with some shimming so you can be on the same page ...

I must say you must be a shim master to handle the 3 minutes of total run time with the MT XL with straight cut gears

[Deckard]

Why is the diff cup plastic? I'm not a mechanical engineer, but when I looked at the diff cup for the first time I thought "where's the 1/8th version?"

When I see the amount of force that is applied to the diffs when just testing.... I feel kind of sorry for that little plastic toy cup. I'm going to give the GPM diff cup a shot.

Also, hard breaking is a diff killer for sure. I'll hit a someone before I'll break hard with my YXL.